Process for the manufacture of alkali-metal compounds.



E. A. ASHCROFT.

PROCESS FOR THE MANUFACTURE OF ALKALI METAL COMPOUNDS.

APPLICATION LED MAR' 12, 1912. llgQ., Patent-edSept. 5,1916` 2SHEETS-SHEET I.

WITNESS ES INVENTO AW* ATTo NEYS E. A. ASHCROFT.

PROCESS FOR THE MANUFACTURE OF ALKALI METAL COMPOUNDS.

APPucAnpN HLED MAR.12. 1912.

1919?,29, Pmentedept. 5,1916.

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EDGAR ARTI-TUR ASHCROFT, OF LONDON, ENGLAND. w

PROCESS FOR. THE MANFACTURE OF ALKALI-METAL COMPOUNDS.

To all whom it may concern:

Be it known that I, EDGAR ARTHUR AsnoRoF'r, a subject of the King ofGreat Britain and Ireland, and residing atv 99. BuckinghampPalace road,in the county of London, England, and at Sande Gaard, Balestrand, Sogn,Norway, electrochemical engineer, have invented new and usefulImprovements in Processes for the Manufacture of Alkali-Metal Compounds,of which the following is a specification. f

It is known that reagents such as ammonia, carbon, hydroxyl (from steam)and the like will react with sodium-lead and potassium-lead alloysproducing the corresponding compounds usually in the fused state buthitherto such processes have not been extensively applied, nor have thenecessary conditions for success been ascertained, or described, thereactions being mostly too slow, or attended by other seriousdifi'iculties.

The object of my present invention is to effect the economicalmanufacture of alkali metals, amids, cyanamids, cyanids and otherproducts (hydrates for instance) from alloys of alkafli metalsin onecontinuous operation.

In carrying my invention into effect ad- Vantage is taken of thediscovery that the aforesaid products in a fused state if brought intocontact with alloys of the alkali metale (for instance With sodiurn-leadoI potassium-lead alloys) under suitable conditions as hereinafterexplained will dissolve large quantities of the alkali metal withoutdissolving the lead and the dis- `solved alkali metal may be afterwardvery conveniently reacted to produce further quantities of the originalcompound or any derivative ther'eof. It is not essential to thisinvention whether the phenomenon observed be a truesolution of the metalin the fused melt or a chemical 'union therewith forming anothercompound, as the original or desired compound is always generated on.reacting the melt with the required reagents exactly as if a puresolution of metal in the' melt takes place. As an example I will eX-plain the production of sodium or potassium amids from sodium orpotassiumalloys with lead. i

I have found by experiment that the alloy must exceed 6 per cent. sodiumor 5 per cent. potassium and must be maintained at a temperature of orabout 4OO centigradc below specification of Letters Patent.

lor stirring. The means 'however which I prefer to employ for thisypurpose are as follows: The body of the fused amid is contained in akettle or reservoir which is attached by means of pipes to the secondcell of an electrolytic apparatus in which the alloys are continuouslyproduced. By

Patented Sept, 1916.,

Application file March 12, 1912. Serial No. 683,376.

These conditions having been.

means of a worm or other pump theamid is` caused to circulat'e somewhatrapidly and to spread out and flow continuously in a shallowstream overa large fiat surface of the molten alloy and finally to collect in awell or Chamber into which it fiows over a. weir of a suitable height('for example one centimeter) above the Constant level of the alloy.From the Chamber or well it flows back into the kettle or reservoir. Itis'convenient to so direct the discharge from' the pump into the cellthat rotary motion of the melt and alloy is set up and maintained. Thereaction may be further assis'ted by agitators.

In the kettle or reservoir and also in the well or any v,otherconvenient part of the apparatus in which there is no free access to thealloy the melt may befcoutinuously treated by passing in slowly a streamof amring-pipe having many small outlets. The

ammonia reacts with the dissolved metal and forms additional quantitiesof fused amid which may be caused to overfiow from the apparatuscontinuously by means of a. fixed level overfiow in the well orelsewhere. In this manner a perfectly continuous process is obtainedltogether with a high rate of reaction and all other conditions necessaryfor successful operation, while the apparatus is simple and durable.-The kettle or reservoir'andfthe secondary cell may be of any convenientform but I prefer a circular form with the well in the center of thesecondary cell and the kettle or reservoir on one side of it. It is alsopossible to employ a kettle or reservoir contained within orpracticallywithin the second vcell or immediately beneath it asdescribed under my application for Letters Patent Serial No. 683,377. o

The accompanying drawing represents in Vertical section in Figure 1 andplan in lFig. 2 a-n apparatusV adapted for the purposes of thisinvention. Fig. 3 is a Vertical section on the line a, b, a, Fig. 2, butI do not limit myself to the precise details illustrated.

1 is the secondary cell in connection with any electrolytic zor otheralloy producing appalratus. The alloy 2 circulates through this ce l.

3 is the amid kettle or reservoir, l` the pump for circulating the amidand 5 the well and circulating pipes to the kettle 3.

The inlet pipe for ammonia or the like is marked 6.

The surface of the moving body of amid or other product is indicatedat7. The alloy for this process may be produced by any known or suitablemeans but T prefer to employ the electrolytic process and apparatusdescribed under my application Ser. No. 683,375. The Adescribedapparatus then becomes the second cell and attachment of thatelectrolytic plant and the whole constitutes means for the continuousmanufacture of the finished product from the raw materials. lnstead ofreacting the di'ssolved i metal in the amid with ammonia it may besubjected' to electrolysis in a separate or connected cell withinsoluble anodes, as described under my application Ser. No. 683,37 7when the amid will be regenerated in an active state for furthersolution lof metal from the alloy and the alkali metal i toF will beobtained atthe cathode.

Similar reactions may be carried out with other bodies for instancefused cyanid dissolves the alkali metal from the alloy and forms acompound which may be at once reacted with cyanoge'nl (HCN),trimethylamin, benzol, or other hydrocarbons, ammonia `and' the like andwill produce more -cyanid, cyanamid, or other compound according toknown reactions. The strength of ,alloy required is the same as for theamid but the temperature must be higher namely about 600? 'centigradeCaustic soda dissolves the metal freely from the alloy at an even lowerpercentage of alkali metal if the temperature be'above 550 centigradeand according to this invention the fused melt is reactedeither withhydroxyl (from wai terV in the forml of steam) direct or with p ammoniafirst :forming amid which is after- Ward reacted with hydrqxyl formingmore 'caustic alkali, all as described under myap- -plication Ser. No.683,37 8. T't is also obvious that according to my apphcation Ser. No.

683,377 alkali metals may be manufactured by electrolyzingthe amid andreturning the Liv/,eee

ammonia. T prefer to maintain an atmosphere of hydrogen (or othergaseous reagentin use) in the whole apparatus in order to completelyeXclude air and at the same time assist the'reactions br, if desired, Tmay maintai-n lan vatmosphere of ammonia in the kettle. lThis conditionis automatically produced by the condition of 'the process in practicalwork. It is convenient to put in communication the free space in thesecond cell and that in the kettle, or reservoir when this does notcontain an atmosphere of ammonia and also to seal the over'lowv by atrap Sto prevent ingress of air.

What ll claim is I 1. The process of manufacturing an alkali metalproduct from an alloy of the alkali metal, which comprises bring'ing afused body of'the alkali metal'product into contact with an alloy'ofsaid alkali metal with a heavy metal, transferring the fused alkalimetal product with its absorbed alkali metal, to a separate reactionchamber apart from that containing'jthe heavy metal alloy, and thereinsubjectirlg4 the absorbed alkali metal to the action of'areagent servingtov convert the same into vthe desired product, substantially asdescribed.

2. The process of manufacturing an alkali metal product from an .alloyof the alkali metal, which comprises circulating a fuse'd' melt of thealkali metal product in intimate contact with an alloy of said alkalimetal with a heavy metal, transferringthe fused alkali metal productwith its absorbed alkali metal, to a separate reaction chamber apartfrom that containing the heavy metal alloy, and therein subjecting theabsorbed alkali metal to the action of a reagenttserving to convert thesame into the desired product, substantially as described.

3. The process of manufacturing sodium amid which comprises bringing abody. of sodium amid intd contact with a sodium lead alloy containing atleast 6 per cent.l s'odium, transferring the `melt so obtained into aseparate reaction vessel and therein reacting the absorbedmetal withammonia.

' 4. The process of manufacturing sodium amid which comprises bringing abody of sodium amid into contact with a sodiumlead alloy containing atleast 6 per rcent. so-` dium at a temperature' of substantially 400 C.,transferring the melt so1 obtained into a separate reaction vessel andtherein reacting the absorbed metal with ammonia.

5. The process ofy manufacturing ,alkali metal substances whichcomprises the step of passing a fused melt of alkali`meta1 substance ina Vshallow stream over a large surface of an alloy ofthe alkali metalWith a heavy metal, transferring 'the meltinto a' separate reactionvessell apart from that containing the heavy metal alloy, and thereinsubjecting the melt to the action of isc themes reagents to transformthe absorbed alkali metal into `the desired product.

6. The process of manufacturing alkali metal substances which comprisesthe step of passing a shallow stream of a fused melt of alkali metalsubstance over a large surface of an alloy of the alkali metal sub-ustance, transferring the melt so obtained into a separate reactionvessel and therein agitating the melt in the presence of reagents toproduce the desired product, and continuously circulating the alkalimetal substance between the second cell of an electrolytic apparatus andthe second reaction vessel, substantially as described.

7. rl`he process of manufacturing an alkali metal product from an alkalimetal alloy, which comprisesbringing a fused melt of the alkali metalproduct into contact with an alloy of the alkali metal with a heavymetal containing at least five per cent. of the alkali metal,transferring the said product With its absorbed alkali metal to aseparate reaction vessel and therein subjecting the melt to the actionof a suitable reagent to obtain the desired product.

8. The process of manufacturing an alkali metal product from an alkalimetal alloy., which comprises bringing a fused melt of the alkali metalproduct into contact With an alloy of the alkali metal With a heavymetal containing at least five per cent. of the alkali metal, and' at atemperature of about lt C., transferring the said product with itsabsorbed alkali metal to a separate reaction Vessel and thereinsubjecting the melt to the action of a suitable reagent to obtain thedesred product.

9. The continuous process of manufacturing an alkali metal compound froman alloV of the alkali metal, which comprises circulating from aseparate reaction Vessel a quantity of fused alkali Vmetal compound intocontact with a current of fused alkalimetal-heavy metal alloy, leadingback said compound With thev alkali metal absorbed from the alloy tosaid separatev reaction chamber and therein subjecting the meltl to theaction of a suitable reagent to convert the absorbe'd alkali metal intothe desired compound. j

10. The continuous process of manufacturing an alkali metal compoundfrom an alloy of the alkali metal, which comprises circulating from aseparate reaction vessel a quantity of fused alkali-metal compound in ashallow stream over the surface of a fused alkali-metal-heavy-metalalloy, leading back said compound with the alkali metal absorhed fromthe alloy to the said separate reaction Chamber and therein sub-vjecting the melt to thevaction of a suitable reagent to convert theabsorbed alkali metal into the desired compound.

In testimony whereof l have signed my name to this specification in thepresence of two suhscribing witnesses.

EDGAR ARTHUR ASHCROFT.

